The present invention relates to a mobile delivery flow equalizer provided with a bunker below the ground or operating level to receive bulk material unloaded from trucks, and with a conveyor belt system to transfer the bulk material from the bunker to subsequent elements in an open-cast equipment chain of operations, particularly screening and reducing installations before being removed by conveyor belts.
Such delivery flow equalizers are predominately employed in solid rock open-cast operations, where growing rubble and ore quantities increasingly require the use of conveyor belt systems. The problem is that the bulk material delivered in heavy-duty trucks of up to 320 tons service load might not be fit to be conveyed on a belt due to too great a quantity at one time. The oversize deliveries must, therefore, be sorted out or reduced. Since the reducing plants cannot handle the great quantities of rock and ore suddenly occurring during the transfer from the trucks, the plants are preceded by the delivery flow equalizers, guaranteeing a uniform delivery.
Several methods are known for unloading the trucks, to transfer the bulk material to the delivery flow equalizers. It is usual to empty the truck from a ramp which can be traveled by trucks starting from a banked up slope. The artificially banked up slope, however, entails the risk of collapse from the weight so that this method is restricted to comparatively light trucks and low level slopes. The ramp following the slope must be formed as a heavy artificial structure, which results in an installation which can no longer be called mobile due to the structural unit of slope and ramp. Another disadvantage is the necessary hoisting form of operation required with a dead load, as well as the time loss incurred in traveling the slope and the ramp. Finally, this method only permits unloading of one truck at a time.
Another past method offers more favorable discharging facilities in that a discharge trench is dug out in the level ground. The trucks are emptied into this discharge trench. To receive the bulk material, however, it is necessary to provide a paddle wheel or similar lifting device, raising and transferring the discharged goods to a conveyor belt system which moves to the next equipment in the processing chain. Furthermore, the trench can only be filled by the trucks from one side. Also, very bulky pieces may cause difficulties in pick-up by the reloading or pick-up device. Finally, it has to be noted that the use of the reloading device considerably increases the cost of the entire plant.
Based on these problems, it is the object of the present invention to improve upon a mobile delivery flow equalizer of the type described in the principal concept as described in claim one so that a most mobile installation provided with low structural requirements, which is of maximum efficiency regarding the receiving and transfer of the bulk goods and which, as a substantial structure, is easily adapted to the varying conditions of solid-rock open-cast operations. This is achieved by using a receiving bunker consisting of an open-top container, structurally joined to the supporting frame of a conveyor belt system, with such container being partially sunk into a prepared excavation provided below the ground operating level, and below the discharge height of the trucks.
The bunker is "mobile" by simply digging out an excavation ion in accordance with the size of the container by means of equipment available and used anyway in open-cast operation. Then the container is sunk into the excavation. The excavated material is partially used to fill in the container so that the trucks may approach it without the necessity of ramps, slopes or other inclines out of the travel plane. Another feature of the invention is that the conveyor belt of the conveyor belt system extends into the container as well as out of it so that the conveyor belt forms essentially the bottom of the container. This results in a simple solution obviating the need for reloading devices, such as the paddle wheels used heretofore. The bulk goods discharged into the container are directly charged onto the conveyor belt, and removed by means of the conveyor belt system laterally from the container towards the next following processing elements.
Preferably, the container is pivotally connected to the supporting frame of the conveyor belt system to swivel around a horizontal axis. This allows the container to adapt to the depth of the excavation, and yet adheres uniformly to the bottom surface. This relieves, in a favorable manner, the supporting frame of the conveyor belt system of the great weight of the bulk material, so that it may be constructed rather light weight in form.
Another feature of the invention is that the conveyor belt system itself rotates around a horizontal pivot, and rests on a scaffold element supported on the level ground. This feature facilitates lifting the bunker container by swiveling the supporting frame of the conveyor belt system around its horizontal pivot support and lifting it out of the prepared excavation. This is of particular advantage because another feature of the invention provides that the scaffold supporting element carrying the conveyor belt system is equipped with a drive, which may be, for example, a caterpillar drive.
By providing a piston cylinder unit engaging the scaffold element on one end and the supporting frame of the conveyor belt system on the other end, the conveyor belt system may be pivoted on the horizontal axis, and an apparatus is provided which is of maximum mobility. By means of the piston cylinder unit, the supporting frame of the conveyor belt system with the bunker container as a structural unit may be easily rotated or swiveled around the horizontal axis, so that the container may be lifted out of the excavation in the level ground. This makes the entire installation freely mobile, if it is arranged on the carriage as proposed by the invention.
An example of the invention is shown on the drawings as follows: